主题：开个帖作为学术翻译问题请教专帖 -- 冰与火

今天就准备把文章投出去了，目标是ACM的TISSEC。投稿前把摘要部分和结论部分贴出来，请河友们扫两眼，提提意见，改改错误。

先贴摘要部分。

A trusted system is an information system whose behavior is expectable. The traditional protection system models, such as access

control matrix model, lack the ability to describe it. In this paper, we conclude three attributes about trusted system.With the

three attributes, we can see the trusted system as an information dealing tool which import information from input ports and export information from output ports, there are no information be generated by trusted system itself.In such a system,the security attribute of the information flow from the input to the output can describe the secure state of the system precisely.

Let the three attributes be our axioms, we build a security theory of trusted system.First,we propose a formal description of the information and information dealing procedures,express information by random variable and express information dealing procedures by mathematical functions of random variable vector,and let the

description be our mathematical tools; then we classify the operations in a trusted system ,build an analysis model of it;we

define the covert channel and normal channel of a trusted system ,prove the normal information flow theorem which gives a necessary condition of the existence of normal information flow;we give formal

definitions of secure knowledge,secure requirement and secure policy, prove the intersection theorem which describes the variety of secure attributes of information in system;at last, based on our information flow theory, we propose a dynamic planar multi layer access control model for trusted system and prove its security,this model implement the secure principles of the BLP model and the Biba model,and provide information exchange channels between the users of different secure level.